1. Field
The present invention relates to information processing systems, and, more particularly, to multi-processor task scheduling in such systems (e.g., for power management in a multiprocessor environment).
2. Description of the Related Art
Many information processing systems include multiple processors. These systems often use a multi-tasking operating system scheduler to assign tasks to the processors. Such schedulers typically assume that all of the processors are identical and thus schedule tasks to processors without regard to performance differences between the processors.
However, modern systems may have multiple processors, each with potentially different or changeable performance characteristics. For example, the instantaneous frequency in each processor can be changed dynamically, effectively creating different performance states and performance ranges for each processor. A conventional task scheduler would not have maximal efficiency in such a system because tasks could be equally scheduled to run on processors with different processing performances or a task could be scheduled to run on a processor that has no performance headroom. Thus, there is a need for an improved scheduler, method of scheduling and for systems which take advantage of such schedulers and scheduling.